. The comparative anatomy of the domesticated animals. Veterinary anatomy. THE FOETUS. 899 tliafc of the principal hippomancs, and if pressed between the fingers, the brown matter coLtaiued in a thin-wallcd sac escaped by the pedicle, and sjjread itself over the external surface of the chorion. There the villosities of the placenta were absent at the margin of the opening, which was surrounded by a whitish areola (Fig. 425, h). " Might it not be admitted, from this disposition, that the hippomanes is developed between the placenta and the uterus, and is carried inward, by pushing before i
. The comparative anatomy of the domesticated animals. Veterinary anatomy. THE FOETUS. 899 tliafc of the principal hippomancs, and if pressed between the fingers, the brown matter coLtaiued in a thin-wallcd sac escaped by the pedicle, and sjjread itself over the external surface of the chorion. There the villosities of the placenta were absent at the margin of the opening, which was surrounded by a whitish areola (Fig. 425, h). " Might it not be admitted, from this disposition, that the hippomanes is developed between the placenta and the uterus, and is carried inward, by pushing before it the chorion and layer of the allantois covering it, until, on reaching the allantoid cavity, it becomes detached, like certain fibrous or cartilaginous bodies in the synovial or serous cavities ?"—F. Lecoq. 4. The Umbilical Vesicle. The umhilical vesicle is a small fusiform or pyriform poiich, lodged in the infuudibulum at the extremity of the umbilical cord. Its fundus adheres to the chorion: the opposite extremity is prolonged to a variable depth in the substance of the cord, and is even continued, in the very young foetus, to the abdominal cavity, by a narrow canal that communicates with the terminal portion of the small intestine. This pouch has a red colour, from its great vascularity; its walls receiving a special artery derived from the anterior mesenteric, the corresponding vein passing to the jwrtal vein. These are the two omphalo- mesenteric vessels. In the last months of foetal life, the umbilical vesicle is always more or less atrophied; its cavity has disappeared, and it is no more than a thin reddish-brown cord. Its vessels also become atrophied in the same mannei-, and nearly always nothing is found but the artery reduced to the dimensions of a thread. 5. The Placenta. In Solipeds, the placenta is composed of a multitude of small tubercles, spread uniformly over the external surface of the chorion, which they ^'"' ^-^• almost completely cover. The
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